In recent years, there are a growing number of systems that display a plurality of images superimposed on each other. In the case of a car-mounted display in particular, various images such as an air-conditioner operation screen, car navigation screen, DVD (Digital Versatile Disk) or TV images need to be displayed superimposed on each other.
Conventionally, as a method for displaying a plurality of images superimposed on each other, there is a proposal of a method having a plurality of video input images, drawings and frame memories corresponding thereto (e.g., see Patent Literature 1).